Positive displacement pumps are more useful to pump liquids than other types of pumps, such as centrifugal pumps. A positive displacement pump may be more efficient, may have less variable output flow rates, and may provide still other advantages compared to other types of pumps.
As with all pumps, positive displacement pumps will require maintenance and repairs over time. This is not necessarily easy to accomplish. For example, pump impellers and drive gears may need to be pressed from shafts, and shafts may need to be press fit to supporting structure within the pump. This may require the services of a special facility, such as a machine shop. Where positive displacement pumps are used far from such facilities, repair becomes more time consuming and expensive.
There exists a need to simplify assembly and disassembly operations to facilitate repair, maintenance, and other operations performed on positive displacement pumps.